Caching

The Flash Designer component allows you to use the server cache to store rendered reports in the preview mode. If you do not use caching, then, when you print and export the report, the designer will send the report to the server-side, consuming Internet traffic and slowing down the process of printing and exporting the report. If you use caching, then, with the specified actions, the previously rendered report will be loaded from cache.

When using caching, it should be taken into account that every report saved in the cache takes up server memory and, with a large number of requests to reports, this can become a critical issue. Therefore, you need to choose from two options - either low memory requirements but high in performance and the volume of transmitted data or low performance requirements and internet traffic but high in memory on the server-side.

You can manage caching with the following properties.

The CacheMode property

This property of the designer enables caching and sets its type. It can take one of the following values, specified in the StiServerCacheMode enumeration:

None – caching is disabled, when printing and exporting, the report will be every time sent to the server-side;

ObjectCache – for caching, the server cache is used. The report object is saved in this (set by default);

StringCache - the current session, in which the report object is saved, is used for caching;

ObjectSession - for caching, the server cache is used, in which the report is saved as a packed string;

StringSession - for caching, the current session is used, in which the report is saved as a packed string.

The CacheItemPriority property

This property sets the priority of the report stored in the server’s cache. It affects the automatic clearing of the server memory in case of memory shortage. The lower the priority is, the greater is the chance of removing information from memory.

The CacheTimeout property

This property specifies the amount of time in minutes for which you want to save the report in the server cache.

The Flash Designer component provides the ability to specify its own methods for working with report caching. For this purpose, a special StiCacheHelper class is used. It contains methods for obtaining a report from the cache and saving the report to the cache. It is necessary to create a new class inherited from StiCacheHelper and reload the above methods which respectively have the names - GetReport and SaveReport.

Default.aspx.cs

...
public class DesignerFxController : Controller
{
    public class StiMyCacheHelper : StiCacheHelper
    {
        public override StiReport GetReport(string guid)
        {
            string path = System.IO.Path.Combine(System.Web.HttpContext.Current.Server.MapPath("~/"), "CacheFiles", guid);
            if (System.IO.File.Exists(path))
            {
                StiReport report = new StiReport();
                string packedReport = System.IO.File.ReadAllText(path);
                if (guid.EndsWith("template")) report.LoadPackedReportFromString(packedReport);
                else report.LoadPackedDocumentFromString(packedReport);
                
                return report;
            }
            return null;

            //return base.GetReport(guid);
        }

        public override void SaveReport(StiReport report, string guid)
        {
            string packedReport = guid.EndsWith("template") ? report.SavePackedReportToString() : report.SavePackedDocumentToString();
            string path = System.IO.Path.Combine(System.Web.HttpContext.Current.Server.MapPath("~/"), "CacheFiles", guid);
            System.IO.File.WriteAllText(path, packedReport);
            
            //base.SaveReport(report, guid);
        }
    }
        
    static DesignerFxController()
    {
        StiMvcDesignerFx.CacheHelper = new StiMyCacheHelper();
    }
}
...

To initialize the work with report caching using the created class, it is enough to set it as the value of the StiMvcDesignerFx.CacheHelper static property in the ASPX page constructor.

Information

If report caching is disabled (the CacheMode designer property is set to None), the specified class will not be used.